[TG] DSM operation out of the water

[jwasko]

My boat has 2 C140W's and a DSM30 networked via a SeatalkHS 8 port switch. I have been experiencing spurious Connection Lost messages from the DSM. The boat is new to me so I don't know the trouble history or software levels. I would like to troubleshoot per FAQ 90 but the boat is now out of the water for the winter.

Is it safe to operate the fishfinder out of the water with the transducer powered? Alternately, can the unit be operated with the transducer disconnected in order to determine the software levels and troubleshoot the power/network connections?

[Tom - Raymarine - Moderator]

Hello jwasko,

No, don't operate any high-power sounder out of the water. Air doesn't provide the same resistance against the face of the transducer as water, which changes (lowers) the impedance of the transducer and can cause a large increase in current being drawn from the sounder. This can quickly damage both sounder and transducer.
In addition, air isn't as effective at cooling transducers as water: a factor in the large, modern Chirp transducers in particular.

It is safe to disconnect the transducer (as long as you power down the sounder module before you disconnect), or you can set Ping Enabled to Disabled in Menu > Fishfinder Setup > DSM Settings.

Regards,
Tom

[Tom - Raymarine - Moderator]

Hello jwasko,

By the way, here's an old document which we used here in Australia to help people in the field diagnose 'DSM CONNECTION LOST' alarms, back in the days when these were a common question. It runs through some of the many possible causes and some tests. It may help.

Regards,
Tom